“…Second, the converse evidence, i.e., improved LTP and enhanced learning abilities, has been achieved by mimicking NCAM function (Cambon et al, 2004) or by L1 or PSA-NCAM over-expression (Wolfer et al, 1998;Rendeiro et al, 2014;Saini et al, 2020). Third, mRNA and protein expression of NCAM, PSA-NCAM, and L1 in different Abbreviations: NCAM, neural cell adhesion molecule; LTP, long term potentiation; CS, conditioned stimulus; US, unconditioned stimulus; PSA, polysialic acid; EMG, electromyographic; OO, orbicularis oculi; CR, conditioned response; Ipsi, ipsilateral; Contra, contralateral. brain areas is regulated by learning and LTP (Ronn et al, 2000;Hartz and Rønn, 2010;Saini et al, 2020;Duncan et al, 2021). Specifically, the expression of these CAMs is modulated in the hippocampus 1-24 h after LTP induction, by training in a memory task (Fazeli et al, 1994;Schuster et al, 1998;Ronn et al, 2000), or after a variety of hippocampaldependent training experiences including passive avoidance training (Doyle et al, 1992a;Fox et al, 1995Fox et al, , 2000Brandewiede et al, 2014), contextual fear conditioning (Merino et al, 2000;Sandi et al, 2003;Maćkowiak et al, 2009), and olfactory (Knafo et al, 2005a,b), and spatial (Sandi, 2004;Venero et al, 2006;Yamagishi et al, 2018) learning tests.…”